The present invention relates to air bag devices mounted in vehicles, and more particularly relates to an air bag apparatus suitable for a passenger seat.
In the air bag apparatus for the passenger seat, an air bag is stored in a container-type retainer, which is covered by a lid. The air bag apparatus is disposed in an instrument panel of a vehicle. When the vehicle collides, an inflator expels a gas, which inflates the air bag. The inflated air bag pushes and opens the lid into the interior of a vehicle cabin, and then expands into the interior of the vehicle cabin.
As for the air bag apparatus of this type, a construction is known in which the lid is connected to the retainer with a belt and is movable in a direction in which the air bag goes out from the instrument panel. In the descriptions hereof, the direction in which the air bag goes out from the instrument panel is referred to as the xe2x80x9cvertical directionxe2x80x9d.
FIG. 3 is a sectional view of such a conventional-type air bag apparatus for the passenger seat. A retainer 20 contains an air bag 21 and an inflator 22 which is disposed under the air bag 21. The retainer 20 is open at the upper surface and is covered by a lid 23. The retainer 20 is provided with hooking members 24 at both sides. The hooking members 24 have hook portions 24a which are inserted into through holes 26 formed in leg portions 25 of the lid 23. The hooking members 24 provided at both sides of the retainer 20 are connected to each other with a belt 30, which is attached to the retainer 20 at the bottom thereof with a rivet 31. The leg portions 25 are provided with attachments 27 at the external surfaces. The attachments 27 clamp an instrument panel 28 at the peripheral portion around an opening 29 formed for receiving the air bag apparatus. Accordingly, the lid 23 is fixed to the instrument panel 28.
According to the above-described air bag apparatus of the conventional type shown in FIG. 3, the belt 30 is attached to the retainer 20 with the rivet 31. Thus, the lid 23 attached to the instrument panel 28 may receive an opposing force from the belt 30, so that the peripheral portion around the opening 29 of the instrument panel 28 and the edge portion of the lid 23 constantly receive stress. In addition, the belt 30 may apply upward pressure to the lid 23 and lift the lid 23 by some amount corresponding to the clearance provided between the attachments 27 and the peripheral portion around the opening 29 of the instrument panel 28. In such a case, the lid 23 slightly protrudes relative to the instrument panel 28.
Accordingly, an object of the present invention is to provide an air bag apparatus which has a construction such that the lid is not supported by the retainer in practice.
An air bag apparatus of the present invention comprises a retainer having the shape of an open container, an air bag which is stored inside the retainer and of which a peripheral portion around an aperture for receiving a gas is attached to the retainer, a lid which covers the open surface of the retainer, and attaching means formed in an instrument panel for attaching the lid to an opening for receiving the lid, wherein one or more members are led around the external surfaces of the retainer, and are attached to the lid with both ends of the members, and wherein the members are not restrained by the retainer so that the lid is movable in the vertical, the longitudinal, and the widthwise directions.
As described above, the members are not restrained by the retainer, so that the lid does not receive the external force generated by elasticity of the members. Thus, the lid is completely free from the retainer while it is attached to the instrument panel by the attaching means. Accordingly, even when there is a positioning error between the retainer and the peripheral portion around the opening of the instrument panel, the lid may easily be fitted into the opening in the regular position.
The attaching member may be combined with the members, and may be formed as extending portions of the members which extend to the bottom surface of the peripheral portion around the opening for receiving the lid. Such a construction makes the lid simpler.
Alternatively, the lid may be provided with leg portions which are disposed along the external surfaces of a pair of walls of the retainer, and the attaching means may be formed as protrusions provided on the leg portions behind the peripheral portion around the opening for receiving the lid. According to such a construction, the members may simply be attached to the lid, so that the construction of the members becomes simpler.
Preferably, a predetermined amount of clearance is provided between the members and the retainer over the entire region of the external surfaces of the retainer. In such a construction, the members are not restrained by the retainer.
The members may be belts, elastic materials such as springs, etc. Various non-elastic materials may also be used as the members. Belts have simple construction, and they are inexpensive.
The belts may be attached to the lid by fixing members. By increasing the number of attachment points for attaching the fixing members, stress applied to the lid from the belts when the air bag apparatus is activated would be distributed.
The lid may be reinforced at parts where the belts are attached. Accordingly, even when the lid receives a large amount of force from the belts when the air bag apparatus is activated, the lid would be sufficiently resistant.
The belts may be provided with non-woven fabrics or sponges on the surface facing the retainer. Such a construction prevents unusual noise when the belts contact the retainer.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed.